Such metal cutting tools require accurate positioning of an operative cutting edge relative to the tool. Precise adjustment of the operative cutting edge position is particularly important for finishing operations. However, adjusting mechanisms require installation space in the tool. Therefore, the adjusting mechanism should preferably be dimensionally compact so as to occupy as little space as possible in the cutting tool. This requirement is especially important in tools used for metal removal inside cavities of the work-piece, such as boring or reaming tools, because the dimensions of the bore limit the maximum diameter of the tool, and thus the space available for installation of the cutting inserts and the adjustment mechanisms in the tool.
U.S. Pat. No. 4,850,757 to Stashko discloses such a reamer comprising a holder having a recess into which a disposable cutting insert is fitted. The insert is held in place by a clamping member which bears against a surface of the insert and which is attached to the holder by a clamping screw. Radial adjustment of the insert can be effected by adjusting screws having camming surfaces which bear against a corresponding camming surface of the insert. However, the insert adjustment and clamping mechanisms occupy considerable space at the working end of the tool.
U.S. Pat. No. 4,425,063 to Striegl discloses a reamer with a flat rectangular reversible cutting bit, possessing a cutting edge extending parallel to a longitudinal axis of a revolvable body. The flat rectangular cutting insert has four indexing positions, and occupies a relatively small space on the revolvable body. The flat rectangular cutting bit is detachably mounted in a recess of the revolvable body. However, the adjusting mechanism in U.S. Pat. No. 4,425,063 precludes radial adjustment of the cutting edge position of the cutting insert.
U.S. Pat. No. 4,611,516 to Hochmuth, et al. discloses a rotary metal cutting tool having a plurality of radially adjustable cutting inserts mounted on the periphery thereof. Each cutting insert is clamped by a clamping jaw, and is urged radially outwardly by an adjusting screw positioned radially inwardly therefrom, thereby occupying considerable space near the center of the tool body, and limiting the number of cutting inserts which can be installed.